1. Field of the Invention
This invention relates to a magnetic picture recording and reproducing apparatus, and more particularly to such an apparatus which can effectively reproduce pictures from a magnetic tape in a fast-forwarding play-back mode or in a rewinding playback mode.
2. Description of the Related Art
FIG. 1 is a block diagram of a prior art magnetic picture recording and reproducing apparatus in a fast-forwarding playback mode.
As shown in FIG. 1, a magnetic tape 1 is supplied from a supply reel, which is on a supply reel turntable 2, to be fed past a rotary cylinder 3 having rotary heads and is transported by a capstan 4 firmly pressed against a pinch roller 5 so as to be taken by to a take-up reel which is on a take-up reel turntable 6.
Referring to FIG. 1, a frequency generator (FG) 8 and a rotation phase detector (PG) 9 are associated with a rotary cylinder motor 7 direct driving the rotary cylinder 3 so as to generate respectively a frequency signal and a rotation phase signal corresponding to the rotation speed of the rotary cylinder 3, and these signals are applied to a rotary cylinder (CY) speed control circuit 10 and a CY phase control circuit 13 respectively.
A speed command signal instructing the speed of the magnetic tape 1 in the fast-forwarding playback mode is generated from a speed command circuit 15 to be applied to each of a reference CY speed generating circuit 11 and a reference CY phase generating circuit 14. A reference rotary-cylinder speed signal and a reference rotary-cylinder phase signal generated from the reference CY speed generating circuit 11 and the reference CY phase generating circuit 14 are applied to the CY speed control circuit 10 and the CY phase control circuit 13 respectively, and a speed error signal and a phase error signal relative to the reference speed and phase of the rotary cylinder 3 are generated from the CY speed control circuit and the CY phase control circuit 13 respectively.
These two error signals are applied to a CY driver circuit 12 which drives the rotary cylinder motor 7.
On the other hand, a frequency signal corresponding to the rotation speed of the capstan 4 is generated from a frequency generator (FG) 18 associated with a capstan motor 17 directly driving the capstan 4 and is applied to a capstan (CAP) speed control circuit 19. The magnetic-tape speed command signal from the speed command circuit 15 is also applied to a reference capstan (CAP) speed generating circuit 20. The reference CAP speed generating circuit 20 generates a reference capstan speed signal corresponding to the magnetic-tape speed command, and this reference capstan speed signal is applied to the CAP speed control circuit 19. A speed error signal relative to the reference speed of the capstan 4 is generated from the CAP speed control circuit 19.
A control signal recorded on the magnetic tape 1 is reproduced by a control head 16 to be applied to a CAP phase control circuit 22. The magnetic-tape speed command signal from the speed command circuit 15 is also applied to a reference CAP phase generating circuit 23. A reference capstan phase signal corresponding to the magnetic-tape speed command is generated from the reference CAP phase generating circuit 23 and is applied to the CAP phase control circuit 22, and a phase error signal relative to the reference capstan phase signal is obtained.
The output signal of the CAP speed control circuit 19 and that of the CAP phase control circuit 22 are applied to a CAP driver circuit 21 which drives the capstan motor 17.
The take-up reel turntable 6 is driven by the capstan motor 17 through a rotation transmission mechanism (not shown) so as to take up the magnetic tape 1 transported by the capstan 4 firmly pressed against the pinch roller 5.
In the prior art magnetic picture recording and reproducing apparatus having the construction shown in FIG. 1, it would be attainable to increase the tape speed in the fast-forwarding playback mode N times as high as that in the record mode, if it were possible to increase the capstan rotation speed as high as N times. However, because of a very small diameter of the capstan 4, there has been inevitably a limitation in increasing the rotation speed of the capstan motor 17 to realize a magnetic tape speed in the fast-forwarding playback mode N times faster than that in the record mode. Thus, the prior art apparatus has had the problem that the desired high-speed picture reproduction from the magnetic tape 1 in the fast-forwarding playback mode cannot be attained.